-- 2,434,604 free full-text articles as of 3/25/15HighWire Press at Stanford University develops and maintains the Web
versions of important journals in biomedicine and other
disciplines.
A list of journals
with free full-text articles online is available.
Request email notification when:notify+additions{at}highwire.stanford.edu new sites, announces significant back files online, etc; notify+subscriptions{at}highwire.stanford.edu subscription policies;notify+az{at}highwire.stanford.edu is updated.

-- approximately 300,000 free full-text articlesThe NASA Astrophysics Data System (ADS) is a NASA-funded project that provides
free access to the full text of articles in astronomy and
astrophysics. Most of the major astronomical journals are included. In
many cases articles published in the current year are not available through
ADS. Articles are available in PDF, GIF, or other electronic formats.

The rest of this list is presented alphabetically:

arXiv.org
-- current count of free full-text articles
arXiv.org (formerly xxx.lanl.gov) is a fully automated electronic archive
and distribution server for research papers. Covered areas include physics
and related disciplines, mathematics, nonlinear sciences, computational
linguistics, and neuroscience. Both preprints and published papers are
available.

CogPrints
An Open Archive of self-archived unrefereed preprints and refereed journal reprints in the
Cognitive Sciences: Psychology, Neuroscience, Behavioral Biology, Linguistics, Artificial Intelligence,
and Philosophy. CogPrints uses eprints self-archiving software developed at the Electronics and Computer
Science Department of the University of Southampton.

DOE Information Bridge
The Information Bridge provides an open source to full-text and bibliographic records of United States
Department of Energy (DOE) research and development reports in physics, chemistry, materials, biology,
environmental sciences, energy technologies, engineering, computer and information science, renewable energy,
and other topics. The Information Bridge consists of full-text documents produced and made available by the
Department of Energy National Laboratories and grantees from 1995 forward. The site also provides a link to
Energy Citations, a database that contains bibliographic records for energy and energy-related scientific
and technical information from the Department of Energy and its predecessor agencies.

GPO Access
The United States Government Printing Office offers free access to the
United States Constitution, the Code of Federal Regulations, the Federal
Register, Congressional documents, U.S. Supreme Court decisions, and other
documents. GPO also provides links to other U.S. government Web sites that
offer full text resources.

National Academy Press
Reports from the National Academy of Sciences, the National Academy of
Engineering, the Institute of Medicine, and the National Research Council
are available online free for the reading from the National Academy Press.

National Center for Health Statistics (NCHS)
NCHS publishes statistical reports on health related issues and is a major
source of health statistics. Hundreds of publications, including the full
text of "Health United States", are available through the Web site.

National Environmental Publications Internet Site (NEPIS)
The National Environmental Publications Information System began in 1997, to offer over 9,000 full text,
online documents of the United States Environmental Protection Agency. Documents that are not available
online can be ordered from the agency through NEPIS.

NCSTRL
NCSTRL is an international collection of computer science research reports
and papers made available for non-commercial use from a number of
participating institutions and archives. NCSTRL provides access to over
20,000 technical reports in computer science.

Psycoloquy
An Open Archive of refereed reprints of all target articles, commentaries and
responses from Psycoloquy, a peer-reviewed journal of Open Peer Commentary, sponsored
by the American Psychological Association, indexed in
PsycINFO, and published since 1990 (Archive is complete).

PubMed Central
The U.S. National Library of Medicine's digital archive of life sciences journal literature.
Access to PMC is free and unrestricted.

ResearchIndex
The NECI scientific literature digital library offers five million citations and over 400,000 full-text documents. Papers are derived from proceedings of symposia, journals, books, and other sources. Links to cited works and to comments from readers are available.

Thomas Legislative Information on the Internet
Through Thomas, the Library of Congress offers the text of bills in the
United States Congress, the full text of the Congressional Record, House
and Senate committee reports, and historical documents.

UNESCO
The UNESCO catalog lists 100,000 UNESCO documents and provides access to
the full text of many of these.

World Bank Group Documents & Reports
The World Bank Group makes more than 14,000 documents available through the Documents
& Reports website. Documents include Project appraisal reports, Economic and Sector Works,
Evaluation reports and studies and working papers.